The ability to grow bone at a site-specific location, in a minimally invasive manner, would have a profound impact on the health and quality of life for up to 50 million Americans who suffer bone defects and diseases. These diseases include post craniotomy resorption, periodontal disease, degenerative disk disease, osteoporosis, and aseptic osteolysis. Together, these diseases cost the United States Healthcare System in excess of $124 billion annually.
Cranial
Over 750,000 craniotomies are performed every year in the United States, to treat a variety of disorders including tumors, traumas, vascular lesions, seizures, decompression, cranioplasty, infections, intracranial cysts, and nerve decompression. Despite this, the skull has been one of the most difficult regions in which to use autograft techniques because of the cranium's propensity for resorption. Many materials and methods have been used including autologous bone grafts, metal plates (titanium, tantalum, stainless steel), hydroxyapatite cement, and methylmethacrylate, each with significant drawbacks.
Periodontal Disease.
The most common treatment for periodontal disease and tooth loosening is extraction and dental implantation or dentures. Over 20% of Americans, approximately 56 million people, have periodontal disease. Periodontal disease accounted for 10% of all dental costs in 1985.
Spinal Disorders
Spine disorder treatments are slowly trending toward minimally invasive techniques for penetrating past the muscle tissues surrounding the spine. Despite this, the solutions to degenerative disks (fusion, herniated disk repair and disk replacement) are still highly invasive procedures resulting in extensive surgical trauma and prolonged recovery times. Over 1 million spinal surgeries were performed last year and this number continues to rise.
Joint Replacements
Over ½ million knee and hip replacement surgeries are performed in the United States every year. The typical age of these patients is 65 years despite the fact that the average age of pain symptom onset is 40 years. The reason for this disparity is that the implants cause bone resorption at the interface, making their maximum useful life less than 15 years.
Overall, the ability to induce rapid, localized bone growth would have a substantial beneficial effect in all the above conditions by reducing morbidity, hospitalization time, recovery time, and costs. The ability to grow bone at specific sites would also have a substantial positive impact on the treatment of bone fractures resulting from osteoporosis. It is estimated that over 24 million people suffer from osteoporosis, resulting in 3 million fractures per year in the United States. In 1995 osteoporotic fractures were estimated at $13.8 billion in direct medical expenses.
DisorderAnnual U.S. CasesCraniotomies750,000Periodontal Disease28,000,000Spinal Surgeries1,000,000Aseptic Osteolysis 500,000Osteoporosis3,000,000Total33,250,000
Bone Morphogenic Proteins (BMPs) are osteogenic compounds. However, BMPs can cause ectopic ossification, making them somewhat difficult and risky to use.